The present invention generally relates to reproducing apparatuses for reproducing a rotary recording medium (hereinafter simply referred to as a disc) recorded with a color video signal, and more particularly to a reproducing apparatus capable of compensating for the phase shift and reproducing a disc recorded with a color video system of any of the three system, that is, a disc recorded with a NTSC system color video signal (hereinafter referred to as an NTSC disc), a disc recorded with a PAL system color video signal (hereinafter referred to as a PAL system disc), or a disc recorded with SECAM system color video signal (hereinafter referred to as a SECAM system disc). The reproducing apparatus according to the present invention is capable of obtaining a finely reproduced picture with a receiver of any one of the above three systems, that is, the NTSC system, the PAL system, or the SECAM system.
Generally, as a color video signal system, there are the NTSC system, the
system, the SECAM system, and the like. The color television broadcasting uses any one of the above systems, and the system used is usually unified within a country. However, in the case of a disc reproducing apparatus, there are times when it is desirable to reproduce a disc of a system other than the color television broadcasting system used in that country, according to the program contents of the video signal recorded in the disc. Accordingly, it is highly desirable for the disc reproducing apparatus to have a construction such that the disc reproducing apparatus can reproduce a disc of any one of the above systems.
Furthermore, it is desirable for the disc reproducing apparatus to be designed so that a color television receiver of any one of the above systems can be connected to this disc reproducing apparatus. By this kind of a design, it becomes unnecessary to manufacture reproducing apparatuses exclusively for one particular system according to the color television broadcasting system used, and a single kind of reproducing apparatus may be used in any country using any one of the above systems. This feature will especially be effective when neighboring countries used different color television broadcasting systems.
In addition, in the reproducing apparatus, due to such causes as irregular rotation of the disc, eccentricity of the disc, and curves formed in the recording surface of the disc, a time-base fluctuation component (hereinafter referred to as jitter) is included within the reproduced color video signal. Accordingly, in the conventional disc reproducing apparatus, a circuit is provided for compensating for the above jitter. This circuit separates a horizontal synchronizing signal from the reproduced color video signal, compares the phases of the separated horizontal synchronizing signal and an output signal of a crystal oscillator, and compensates for the jitter by use of an output error signal obtained as a result of the phase comparison.
However, the jitter within the reproduced color video signal could not be sufficiently compensated, by use of the jitter compensation circuit alone, in the above conventional reproducing apparatus. There was a disadvantage in that some jitter still remained within the reproduced color video signal after performing jitter compensation by the above jitter compensation circuit. On the other hand, generally, an automatic phase compensation circuit (APC circuit), an automatic chrominance control circuit (ACC circuit), and the like are provided in a television receiver. However, the television receiver is generally designed to receive broadcast signals having no jitter and displays a received image on the screen, and measures are not taken with respect to signals having jitter. Hence, when the reproduced signal in which some still remains as described above, is supplied as it is to the television receiver, the hue and color saturations of the reproduced color picture varies according to the performance of the APC circuit and the ACC circuit which differ according to the manufacturer of the television receiver. Therefore, there was a disadvantage in that a reproduced color picture having a regular and stable quality could not be obtained.